<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            width: 200px;
            height: 200px;
            background-color: pink;
        }
    </style>
</head>
<body>
  <div></div>

  <script>

    var div = document.querySelector('div');
    div.onclick = function() {
        div.style.backgroundColor = 'purple';
        div.style.width = '500px';
    }
  </script>





    
</body>
</html>